Self-soldering thermal protector.



PATENTED NOV. 7, 1905.

P. B. 000K. SELF SOLDERING THERMAL PROTECTOR.

APPLICATION FILED MAB.26, 1904.

Inventor:

Wilnesses:

yr wzub.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Nov. '7, 1905.

Application filed March 26,1904- Serial No. 200,171.

To all whmn it may concern.-

Be it known that I, FRANK 15.00011, a citizen of the United States, residing at (lhicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Self-Soldering Thermal Protectors, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to thermal protectors for electric circuits. my object being to provide a simple and efiicient protector which automatically restores itself to operative condition after operation.

Heretofore thermal protectors of the selfsoldering type have generally been provided with a heat-producing element in the form of a coil of fine Wire adapted to soften a fusible material by the heat produced in the said coil upon the passage of an abnormally large current therethrough, and thereby allow the protector to operate, the cooling of the fusible material after operation again restoring the parts of the protector to operative condition. In my present invention I employ a piece of resistance material, preferably graphite, as the heat-producing element and adapt same to soften a heat-susceptible material upon the passage of an abnormally large current therethrough, and thereby allow a conducting member to turn upon the said resistance material, and thus control a circuit, the said conducting member being again secured in an operative position by the cooling action of the heat-susceptible material after the device has operated. I also provide a spring member adapted to hold the said resistance material against rotation and another spring member adapted to engage the said conducting member and turn same upon the resistance material when the heat susceptible material is softened.

I will more particularly describe my invention by reference to the accompanying drawings, illustrating same, in which-- Figurel is a side elevation of the protective device. Fig. 2 is an end view of Fig. 1. Fig. 3 is a cross-sectional view of the protective device taken on line w 00 of Fig. 2, and Fig. 4: is a view showing the protective device in an operative position in relation with its contactsprings and circuit-conductors.

Like characters refer to like parts in the several figures.

a is a cylindrical piece of resistance matea circuit-controlling means.

' rial, preferably graphite, flattened at each end, as shown at to, and provided with an annular groove at its middle, in which groove a metal ring 0 is held. The ring 0" is preferably split, as at 6, so that it may be sprung over the larger part of the block a when put in place in the said groove and is provided with a series of teeth 0 therearound, each tooth being adapted to engage The split (3 in ring 0 is cut diagonally across the ring, so

that the circuit-controlling means will engage a tooth c on each side of the split a and not tend to spring the ring apart, as it would if the split 0 were cut parallel with the teeth 0 and the circuit-controlling means were engaged with a tooth next to the split 6. In the bottom of the groove (Z are a number of holes (P6P filled with a heat-susceptible material (Z, which adheres to the ring 0 and thereby holds the latter from turning upon a when the heat susceptible material is cool. This heat-sus-= ceptible material (I may be a metallic solder or a fusible wax, as the ring 0 makes good contact with the resistance material a, due to the spring in 0 without depending on the conductivity of the heat-susceptible material (Z.

The inner surface of ring 0 may be rough, so

asto allow the heat-susceptible material to more readily adhere thereto.

Spring g is provided with ears 0", one for each flattened portion 6 of the protector, each ear g being slotted, as at g. The protector is inserted between the ears 9 the portions 6 6 being inserted into the respective slots g g, which prevent the protector from turning.

The ears 9 tend to'spring together,and thereby 1 make good contact with the cylindrical portion of the graphite block a. Spring f is provided with a catch f adapted to engage a tooth c of the protective device, and thereby tend to turn the latter upon its support.

It is a ground-plate against which spring f rests when released from the protector. Springs g and f and plate It may be mounted on any suitable base 7). Conductors Z, m, and a are connected to g, f, and it, respectively, by binding-screws v1, 7', and 7c, conductor a being preferably connected to earth.

The circuit through the protector is from line conductor Z, through spring 5, cars g", resistance material a, ring 0 and spring f, to line conductor m.

When an abnormally large current traverses the resistance material a, the heat produced therein softens the heat-susceptible material TIC (Z and allows spring f to turn ring 0 upon the resistance body a, and thereby release itself from the tooth c and break the circuit through the protector, spring f taking the position f Fig. 4. When the heat-susceptible material cools, the ring 0 is again secured to the resistance-body a in a new operative position, thereby permitting catch f to be again engaged with a tooth 0 as before. The protective device may be operated over again and again, as just described, each time restoring itself to operative condition.

I do not Wish to limit this invention to the particular details of construction as herein shown, as many modifications may be made Without departing from the principles involved.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. in a thermal cut-out for electric circuits, the combination of a cylindrical piece of resistance material flattened at each end, an annular groove in the resistance material, a series of holes in the said groove, a metallic ring placed in the said groove, heat-susceptible material in the said holes and adapted to hold the said ring in a fixed position, means for securing the device in a fixed position, and means for engaging the said ring and thereby turning same, when the heat-susceptible material is softened.

2. In a thermal protector for electric circuits, the combination of a cylindrical piece of homogeneous resistance material flattened at each end thereof, an annular groove in the resistance material midway between the flattened ends, a series of holes in the bottom of the said groove, a metallic ring in the said groove, a series of teeth on the said ring, a diagonal split in the said ring adapted to allow the latter to be sprungin the said groove, heatsusceptible material in the said holes and adapted to hold the said ringfrom turningin the said groove, spring means adapted to engage the said flattened ends of the resistance material and thereby hold the protector in a fixed position, and a circuit-controlling spring adapted to engage a tooth of the said ring and to turn the latter within the said groove, upon the passage of an abnormally large current through the protector, and thereby open the circuit, substantially as described.

3. In a thermal cut-out for electric circuits, thecombination of a cylindrical piece ofgraphite flattened at each end thereof, an annular groove in the said graphite, a series of holes in the said groove,a metallic ring placed in the said groove, heat-susceptible material in the said holes and adapted to hold the said ring in a fixed position, means for securing the device in a fixed position, and means for engaging the said ring and thereby turning same, when the heat-susceptible material is softened.

4. In a thermal protector for electric circuits, the combination of a cylindrical piece of graphite flattened at each end thereof, an annular groove in the graphite midway between the flattened ends, a series of holes in the bottom of the said groove, a metallic ring in the said groove, a series of teeth on the said ring, a diagonal split in the said ring adapted to allow the latter to be sprung in the said groove, heat-susceptible material in the said holes and adapted to hold the said ring from turningin the said groove, spring means adapted to engage the said flattened ends of the graphite and thereby hold the protector in a fixed position, and a circuit-controlling spring adapted to engage a tooth of the said ring and to turn the latter within the said groove, upon the passage of an abnormally large current through the protector, and thereby open the circuit, substantially as described.

5. In a thermal protector for electric circuits, a piece of resistance material, a conductor surrounding the resistance material, indentures in the resistance material, heat-susceptible material in the said indcn tu res for normally holding the said conductor from turning, and means for engaging the said conductor to turn same upon the resistance material when the heat-susceptible material is softened.

6. In a thermal protector for electric circuits, a piece of resistance material, an annular groove in the resistance material encircling same, a conductor in the said groove, indentures in the said groove, heat-susceptible material in the said indentu res for normally holding the said conductor from moving, and means for engaging the said conductor to move same upon the resistance material when the heat-susceptible material is softened.

7. In a thermal protector for electric circuits, a piece of homogeneous resistance material, an annular groove in the resistance material encircling same midway between the ends thereof, a conductingring in the said groove, indentures in the said groove, heatsusceptible material in the said indentures for normally holding the ring from turning, a series of engaging devices on the said ring, and circuit-controlling means for engaging an engaging device to turn the said ring upon the resistance material when the heat-susceptible material is softened.

8. In a thermal protector for electric circuits, a piece of resistance material, an annular groove in the resistance material encircling same midway between the ends thereof, a conducting-ring in the said groove, indentures in the said groove, heat-susceptible material in the said indentures for normally holding the ring from turning, and means for engaging the said ring to turn same upon the resistance material when the heat-susceptible material is softened.

9. In a thermal protector for electric circuits, a piece of resistance material, indentures in the resistance material, a conducting-ring encircling the resistance material, heat-susceptible material in the said indentures for normally holding the ring from turning, a series of engaging devices on the said ring, and means for engaging an engaging device to turn the said ring upon the resistance material when the heat-susceptible material is softened.

10. In a thermal protector for electric circuits, a piece of graphite for inclusion in the circuit, a conductor surrounding the graphite, indentures, in the graphite, heat-susceptible material in the indentures for normally holding the said conductor from turning, and means for engaging the said conductor to turn same upon the graphite when the heat-susceptible material is softened.

11. In a thermal protector for electric circuits, a piece of graphite, an annular groove in the graphite encircling same midway between the ends thereof, a ring in the said groove, indentures, or the like, in the said groove, heat-susceptible material in the said inclentures for normally holding the ring from turning, a series of engaging devices on the said ring, and means for engaging an engaging device to turn the said ring upon the graphite when the heat-susceptible material is softened, the cooling of the heat-susceptible material after operation again securing the said ring to the graphite for another operation.

12. In an electrical circuit-protector of the character described, resistance material for producing heat, a groove in the resistance material, a conductor carried by the groove and encircling the resistance material, heatsusceptible material normally holding the said conductor in the said groove, and means for turning the said conductor upon the resistance material when the heat-susceptible material is softened.

In witness whereof I hereunto subscribe my name this Q ith day of March, A. D. 1904.

FRANK B. COOK.

Witnesses:

J NO. F. TOMPKINS, HARRY B. ELMERS. 

